Air shutter for gas burners



May 12, 1953 D. F. JONES AIR SHUTTER FOR GAS BURNERS Filed Aug. 8, 1949 IN V EN TOR.

Patented May 12, 1953 AIR SHUTTER FOR GAS BURNERS Don F. Jones, Lansing, Mich, assignor to Motor Wheel Corporation, Lansing, Mich, a. corporation of Michigan Application August 8, 1949, Serial No. 109,138

14 Glaims. 1

This invention relates to. an air shutter for a gas burner.

It is common practice in gas burner structure to flare the end of the mixing or Venturi tube and place a shutter thereon which can be adjusted to regulate the amount of air entering the mixing tube. This shutter must be movable and yet capable of being held in any adjusted position. To accomplish this end it is common practice to provide a slot in the shutter and a set screw which passes through the slot. and screws into a hole in the endoi the Venturi tube. To adjust this type of shutter requires that the screw be loosened, the shutter adjusted and the screw tightened.

Itis an. object of this invention to produce an air shutter for a gas burner which is simpler than the shutters heretofore used, which can be readily adjusted manually at any time without the need of any tools or preparatory operations.

This invention contemplates i an inexpensive shutter which can be easily and quickly adjusted to control the air entering the mixing tube, which will remain in any position to which it is adjusted, and which can be readily disassembled for clean ing at any time.

Fig. 1 is a top plan view showing my shutter mounted on the Venturi tube of a gas burner.

Fig. 2 is a section along the line 22 of Fig. 1.

Fig. 3 is a bottom plan view of my shutter taken along the line 3-3 of Fig. 2.

Fig. 4 is a perspective view of the flared end of the Venturi tube with my shutter mounted thereon. v

Fig. 5 is. a perspective of the spring clip which is used for securing the shutter to the tube.

Fig. 6 is a fragmentary detail showing the keeper for the spring clip."

Referring more particularly to the drawings there is shown a gas burner l and a conventional Venturi or mixing tube 2 secured thereto. The inlet end 3 of the venturi is flared and provided with a spider 4. Spider 4 has a central opening into which fits the fuel-gas nipple or tube 5 for supplying fuel-gas to the mixing tube 2. Spider 4 divides the inlet end of the Venturi tube 2 into two elliptical openings 6.

The shutter I comprises a circular disc 8 having a circumferential flange 9. The shutter is provided with two elliptical, openings I0. corresponding in size and contour to openings 6. Shutter l is also provided with an opening H through which the nipple, 'ipasses. Venturi tube 2 and shutter 1 can be. made from-conventional materials by conventional methods and, by way of illustration, the tube 2 and shutter 1 can be either stamped or cast metal.

Flange ii is providedwith two openings 12 positioned preferably diametrically oppositenotch i3 in flange 9.

The legs of a hairpin spring l4. pass through openings l2 and the ends it of the legs are bent back upon themselves as shown. The

turned-back ends 15 arelsmaller than openings. [2

so that the hairpin spring can be inserted through the openings l2. Turned-back ends l5 are easier to handle since they do not present sharp corners to the fingers when they are grasped between the,

positioned over the flared end 3 of thetube with;

the legs it of the spring clip l4 straddling, the flared end 3, as shown in the dotted lines, Fig. 2; The legs it are thereafter flexed towardv each I other and toward the inlet end 6 of the Venturi tube and the ends thereof interengaged in notch 53, as shown inFigs. 1, 2 and 4. The tension in the spring legs it when fastened in the notch l3 of the shutter lis such that the spring l4 draws the shutter l axially toward or against the inlet end of the Venturi tube 2 and. the spring legs l6 resiliently and frictionally engage. the flared end 3 of tube 2. Thus, the shutter 1 is held snugly against th end of the Venturi tube. so that it will 1 remain in any position to which it is. adjusted but the shutter is not held so firmly thatit cannot be rotated manually against the friction of the shutter againstthe end of the tube and, the friction of the spring against the. side wall-of the tube.

In Fig. 2 the shutter is shown wide open in the full lines with the openings in. of the shutter coinciding with the openings 6 inthe end of the venturi. To cut down the amount of air flowing into the Venturi tube 2, shutter 'l' is adjusted by simply manually rotating the same to any position desired. One such adjusted position is indicated in the dotted lines in Fig. 2.

hold the shutter in its adiustedposition permanently or until it is again manually rotated to a,

new position of adjustment.

To disassemble, the shutter from the tube; it is only necessary to. draw the ends 15 of the springs toward each other, Fig. 2, and then move them outwardly of notch I3 to disengage the spring fingers from' the notch l3 whereupon the springs flex or spring back to their open position, dotted line showing Fig. 2, which releases the shutter and Friction be-, tween shutter I and the inlet end of tube 2 and. between the tube 2 and the spring fingers [I 6 will permits the same to be withdrawn from the end of the Venturi tube 2.

I claim:

1. A shutter assembly for the mixing tube of a gas burner comprising a shutter and a hairpin spring, a connection between the bight portion of said spring and the peripheral portion of said shutter, and a keeper fixed on the peripheral portion of said shutter and positioned generally diametrically opposite said connection and adapted for interengagement with the free ends of said spring, said spring extending generally diametrically of said shutter between said connection and said keeper when the free ends of said spring are engaged within said keeper.

2. A shutter assembly for the mixing tube of a gas burner comprising a shutter in the form of a substantially circular disc having an air opening therein and a circumferential axially extending flange substantially perpendicular thereto, a keeper in the form of a notch in said flange, and a hairpin spring connected to the flange generally diametrically opposite said notch and having its free ends adapted for releasable interengagement with said keeper, said spring extending generally diametrically of said shutter.

3. The shutter assembly claimed in claim 2 wherein the connection between the spring and the flange consists of spaced openings in the flange through which the fingers of the spring pass with the bight portion or the spring positioned on the outside of the flange.

4. The combination claimed in claim 2 wherein the spring fingers are normally generally straight and the distance between the spring fingers is normally substantially less than the diameter of said shutter.

5. The combination claimed in claim 4 wherein the spring fingers straddle the center of said shutter.

- 6. A shutter assembly for the mixing tube of a ga burner comprising a shutter and a pair of spring fingers each having one end connected to the shutter adjacent its periphery and its opposite free end releasably connected to the shutter adjacent its periphery, and a keeper on the periphery of said shutter for releasably interengaging the free ends of said springs, said keeper being positioned generally diametrically opposite the said connection between the said fingers and the periphery of said shutter, said spring fingers when engaged by said keeper extending in a direction generally across the shutter.

7. In combination with a mixing tube for a gas burner, a shutter positioned over the inlet end of the tube and resilient means straddling the inlet end of the tube, extendin in a direction generally across the shutter in engagement with the tube, and connected at its opposite ends to the shutter for securing the shutter on the end of the tube and for drawing the shutter axially against the end of the tube to produce a friction contact between the shutter and the tube whereby the shutter can be swivelled on the end of the tube and frictionally retained in any position to which it is adjusted.

8. In combination with a mixing tube for a gas burner, the said mixing tube having a flared inlet end, a shutter having an air inlet opening therein and positioned over the inlet of the flared end of the tube, and resilient means straddling the flared inlet end of the tube and connected at its opposite ends to the shutter for securing the shutter on the end of the tube and for yieldably drawing the shutter axially against the end of the tube to produce a friction contact, said resilient means engaging the flared end of the tube and being flexed thereby in a direction radially and axially of the tube whereby the shutter can be swivelled on the end of the tube and frictionally retained in any position to which it is adjusted.

9. The combination claimed in claim 8 wherein one of the ends of said resilient means is releasably interengaged with said shutter whereby upon disengagement of said resilient means with the shutter the said shutter can be removed from the tube.

10. The combination claimed in claim 8 wherein said resilient means takes the form of a pair of wire spring fingers bowed generally axially and radially of said tube.

11. The combination claimed in claim 8 wherein said resilient means takes the form of a hairpin spring and wherein the shutter is provided with a notch in which the ends of the spring fingers are adapted to releasably interengage.

12. In combination with a mixing tube for a gas burner, a shutter having an air inlet opening therein positioned over the inlet end of the tube, said shutter having a circumferential flange overlapping the end of the tube, and a spring clip mounted on said flange, extending across the shutter and yieldably gripping the end of said mixing tube for securing the shutter on the end of the tube, said clip having a frictional contact with the tube whereby the shutter and clip can be rotated to adjust the shutter with respect to the end of the tube and held in adjusted position by said frictional contact.

13. The combination claimed in claim 12 wherein the inlet end of the tube is flared and the clip comprises a pair of spring fingers straddling the flared end of the tube and under tension both axially and radially of said tube whereby the clip cooperates with the flared end of the tube for holding the shutter on the tube and for drawing the shutter axially against the end of the tube and in whatever position the shutter is adjusted by swivelling the same on the end of the tube. 1

14. The combination claimed in claim 13 wherein the clip is in the form of a hairpin spring and the flange is provided with a pair of openings through which the spring fingers pass, and a notch positioned substantially diametrically opposite the two openings in which the free ends of the spring fingers releasably interengage the flange.

. DON F. JONES.

References Cited in the file of this patent UNITED STATES PATENTS Number 

